DropDownList “has a SelectedValue which is invalid because it does not exist in the list of items”

Question

I have a ASP.NET DropDownList, which I data-bind to a list of objects, and then it throws an exception. This error is driving me nuts, because the message is wrong, and the

Answer 1

It may be worth first databinding and then adding your blank value. Something along the lines of:

_ddlRequest.Datasource = request;
_ddlRequest.DataBind();
_ddlRequest.Insert(0, new ListItem("", ""));

The only reason I suggest this is that I came across this before and after banging my head in frustration for a while just settled on doing it this way instead.